BreathePulse paces with the iPhone's Taptic Engine. Make sure your iPhone isn't in Silent mode with system haptics disabled (Settings → Sounds & Haptics), and that "Haptics" is turned on in BreathePulse → Settings. Holding the phone in your hand — rather than resting it on a table — makes the pulses much easier to feel.
No. BreathePulse is haptics-only by design, so you can pace a session with the screen off and without disturbing anyone around you.
Box (4-4-4-4) is a balanced all-rounder. Relaxing 4-7-8 has a long exhale and is nice for winding down. Coherent (5.5 in, 5.5 out) is smooth and even. Try each for a couple of minutes and keep the one that feels best.
Yes, optionally. Turn on "Save mindful minutes to Health" in Settings and grant permission. Finished sessions will then appear as mindful minutes in Apple Health. It's off by default and you can turn it off any time.
On your device, in SwiftData. Nothing is sent anywhere. Deleting the app removes everything.
Drop us an email with your iOS version, which rhythm you were using, and a short description of what you did and what happened. Screenshots help.